Security readout for executives and security teams
Plain-English summary
This flaw can let an unauthenticated remote attacker crash an affected Cisco Firepower Threat Defense device by exhausting memory with heavy TCP traffic. The business impact is availability: security enforcement or traffic handling may be interrupted while the device reloads. The bundle does not identify affected version ranges or fixed releases.
Executive priority
Treat this as a high-priority availability risk for exposed Cisco FTD deployments. It does not indicate data theft or integrity compromise, but device reloads can disrupt security controls and network availability. Validate exposure first, then remediate according to Cisco guidance.
Technical view
CVE-2020-3563 is a CWE-400 resource consumption issue in Cisco FTD packet processing. Inefficient memory management can allow remote unauthenticated TCP packet floods to exhaust system memory, causing an unexpected reload. CVSS v3.0 is 8.6, with network attack vector, low complexity, no privileges, no user interaction, and high availability impact.
Likely exposure
Exposure is most relevant for organizations running Cisco Firepower Threat Defense Software on devices reachable from untrusted networks. The provided bundle lists the affected product but does not include specific affected versions, CPEs, deployment roles, or fixed releases.
Exploitation context
The source bundle describes a remote unauthenticated denial-of-service condition. It does not cite known active exploitation, and the CVE is not marked as CISA KEV in the provided data. Treat exploitation status as unconfirmed from these sources.
Researcher notes
The record supports a remote unauthenticated DoS with CVSS 8.6 and CWE-400. Evidence is incomplete for version ranges, exact affected configurations, fixed releases, and real-world exploitation. Avoid assuming exploit maturity beyond the vendor and CVE descriptions.
Mitigation direction
- Review Cisco’s advisory for affected releases and official remediation guidance.
- Check Cisco support channels for fixed or recommended FTD software versions.
- Prioritize remediation for FTD devices exposed to untrusted networks.
- Plan maintenance windows because remediation may require device software updates.
- Monitor affected devices for memory exhaustion or unexpected reloads.
Validation and detection
- Inventory all Cisco Firepower Threat Defense deployments and software versions.
- Compare deployed versions against Cisco’s advisory and support documentation.
- Identify FTD devices reachable from internet or untrusted network segments.
- Review device logs for unexpected reloads or memory exhaustion events.
- Confirm remediation status after applying Cisco-recommended updates or controls.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-3563 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.6 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.6HighVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20201021 Cisco Firepower Threat Defense Software TCP Flood Denial of Service VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.